采用C18毛细管整体柱作为固相微萃取整体柱,构建在线固相微萃取-高效液相色谱联用系统,同步富集检测环境水样中的5种苯氧羧酸类除草剂。详细考察了联用系统运行条件对富集检测的影响。联用系统运行最佳参数为：固相微萃取整体柱长度20 ...采用C18毛细管整体柱作为固相微萃取整体柱,构建在线固相微萃取-高效液相色谱联用系统,同步富集检测环境水样中的5种苯氧羧酸类除草剂。详细考察了联用系统运行条件对富集检测的影响。联用系统运行最佳参数为：固相微萃取整体柱长度20 cm,进样流速0.04 m L/min,进样13 min,洗脱流速0.02 m L/min,洗脱5 min。在最佳条件下,5种苯氧羧酸类除草剂的检出限为：9μg/L（苯氧丙酸）、4μg/L（2-（2-氯）-苯氧丙酸）、4μg/L（2-（3-氯）-苯氧丙酸）、5μg/L（2,4-二氯苯氧乙酸）、5μg/L（2-（2,4-二氯苯氧基）丙酸）。与HPLC系统直接进样对比,联用系统对5种检测对象表现出优良的富集能力。5种苯氧羧酸类除草剂的回收率在79.0%～98.0%之间（RSD≤3.9%）。该方法成功应用于水样中5种苯氧羧酸类除草剂的检测,结果令人满意。展开更多
Culturable thermophilic microorganisms were enriched from samples collected from Lau Basin hydrothermal vents in artificial seawater medium at 45 ℃ and pH 7.0. Microbial diversities of the enriched communities were d...Culturable thermophilic microorganisms were enriched from samples collected from Lau Basin hydrothermal vents in artificial seawater medium at 45 ℃ and pH 7.0. Microbial diversities of the enriched communities were defined by performing a restriction fragment length polymorphism （RFLP） analysis of 16S rRNA gene sequences with enzymes MspI and Hin6 I. A total of 14 phylotypes have been detected by the RFLP patterns identified for 16S rRNA clone libraries of the enrichment. Analysis of sequences showed that at least four bacterial divisions presented in the clones libraries. The phyla Proteobacteria and Firmicutes were the most dominant groups. The majority of the sequences included in this analysis affiliated with Gamma Proteobacteria （71%） and Bacillus （23%）. Scanning electron micrographs revealed that there were abundant rod and coceoidal forms encased in sulphur and sodium chloride precipitate. These results revealed that there were a diversity of moderate thermophilic bacterial populations thrived in Lau Basin hydrothermal vents that were previously not detected by either molecular retrieval or strain purification techniques.展开更多
Metastasis usually presents in the different courses of tumor diseases and associates with poor prognosis.Circulating tumor cells(CTC) are considered to be essential for conforming metastasis and can be detected in tu...Metastasis usually presents in the different courses of tumor diseases and associates with poor prognosis.Circulating tumor cells(CTC) are considered to be essential for conforming metastasis and can be detected in tumor patients' peripheral blood.CTC are not easily detected by conventional cytology methods because of their low frequency in peripheral blood.Our article reviews the recent research results on this subject,and also discusses the problems and prospects in this area.展开更多
In this work, a binary-mixed-brushes-coated (BBC) capillary with switchable protein adsorption/desorption properties was developed and applied for on-line preconcentration of proteins. Firstly, amine-terminated poly(2...In this work, a binary-mixed-brushes-coated (BBC) capillary with switchable protein adsorption/desorption properties was developed and applied for on-line preconcentration of proteins. Firstly, amine-terminated poly(2-methyl-2-oxazoline)(PMOXA-NH2) and thiolterminated poly(acrylic acid)(PAA-SH) were synthesized by using cationic ring-opening polymerization (CROP) and reversible addition fragmentation chain transfer (RAFT) polymerization, respectively. Then, the BBC capillary based on poly(2-methyl-2-oxazoline)(PMOXA) and poly(acrylic acid)(PAA) was prepared by sequentially grafting of PMOXA-NH2 and PAA-SH onto fused-silica capillary inner surface through poly(dopamine)(PDA) as an anchor. The obtained PMOXA/PAA coating formed on the capillary or capillary's raw material was characterized in terms of the thickness, surface chemical composition by using scanning electron microscope (SEM) and X-ray photoelectron spectrum (XPS). The switchable protein adsorption/desorption performance of the BBC capillary was investigated by using fluorescence microscope under di erent solutions with certain pH and ionic strength(I). The results showed that bovine serum albumin (BSA) could be adsorbed on BBC capillary at pH=5.0 (I=10^-5 mol/L), and then the adsorbed BSA could be released at pH=9.0 (I=0.1 mol/L). This switchable protein adsorption/desorption property of coated capillary was then used to preconcentrate proteins on-line for increasing the detection sensitivity of BSA in capillary electrophoresis (CE). With this method, a sensitivity enhancement factor (SEF) more than 5000 for BSA detection was obtained.展开更多
文摘采用C18毛细管整体柱作为固相微萃取整体柱,构建在线固相微萃取-高效液相色谱联用系统,同步富集检测环境水样中的5种苯氧羧酸类除草剂。详细考察了联用系统运行条件对富集检测的影响。联用系统运行最佳参数为：固相微萃取整体柱长度20 cm,进样流速0.04 m L/min,进样13 min,洗脱流速0.02 m L/min,洗脱5 min。在最佳条件下,5种苯氧羧酸类除草剂的检出限为：9μg/L（苯氧丙酸）、4μg/L（2-（2-氯）-苯氧丙酸）、4μg/L（2-（3-氯）-苯氧丙酸）、5μg/L（2,4-二氯苯氧乙酸）、5μg/L（2-（2,4-二氯苯氧基）丙酸）。与HPLC系统直接进样对比,联用系统对5种检测对象表现出优良的富集能力。5种苯氧羧酸类除草剂的回收率在79.0%～98.0%之间（RSD≤3.9%）。该方法成功应用于水样中5种苯氧羧酸类除草剂的检测,结果令人满意。
基金Project(200805032) supported by Grands from Scientific Research Program of Marine Public Welfare Industry of ChinaProject (DYXM-115-02-2-07) supported by China Ocean Mineral Resources R&D Association (COMRA)
文摘Culturable thermophilic microorganisms were enriched from samples collected from Lau Basin hydrothermal vents in artificial seawater medium at 45 ℃ and pH 7.0. Microbial diversities of the enriched communities were defined by performing a restriction fragment length polymorphism （RFLP） analysis of 16S rRNA gene sequences with enzymes MspI and Hin6 I. A total of 14 phylotypes have been detected by the RFLP patterns identified for 16S rRNA clone libraries of the enrichment. Analysis of sequences showed that at least four bacterial divisions presented in the clones libraries. The phyla Proteobacteria and Firmicutes were the most dominant groups. The majority of the sequences included in this analysis affiliated with Gamma Proteobacteria （71%） and Bacillus （23%）. Scanning electron micrographs revealed that there were abundant rod and coceoidal forms encased in sulphur and sodium chloride precipitate. These results revealed that there were a diversity of moderate thermophilic bacterial populations thrived in Lau Basin hydrothermal vents that were previously not detected by either molecular retrieval or strain purification techniques.
文摘Metastasis usually presents in the different courses of tumor diseases and associates with poor prognosis.Circulating tumor cells(CTC) are considered to be essential for conforming metastasis and can be detected in tumor patients' peripheral blood.CTC are not easily detected by conventional cytology methods because of their low frequency in peripheral blood.Our article reviews the recent research results on this subject,and also discusses the problems and prospects in this area.
基金supported by the National Natural Science Foundation of China (No.21674102)
文摘In this work, a binary-mixed-brushes-coated (BBC) capillary with switchable protein adsorption/desorption properties was developed and applied for on-line preconcentration of proteins. Firstly, amine-terminated poly(2-methyl-2-oxazoline)(PMOXA-NH2) and thiolterminated poly(acrylic acid)(PAA-SH) were synthesized by using cationic ring-opening polymerization (CROP) and reversible addition fragmentation chain transfer (RAFT) polymerization, respectively. Then, the BBC capillary based on poly(2-methyl-2-oxazoline)(PMOXA) and poly(acrylic acid)(PAA) was prepared by sequentially grafting of PMOXA-NH2 and PAA-SH onto fused-silica capillary inner surface through poly(dopamine)(PDA) as an anchor. The obtained PMOXA/PAA coating formed on the capillary or capillary's raw material was characterized in terms of the thickness, surface chemical composition by using scanning electron microscope (SEM) and X-ray photoelectron spectrum (XPS). The switchable protein adsorption/desorption performance of the BBC capillary was investigated by using fluorescence microscope under di erent solutions with certain pH and ionic strength(I). The results showed that bovine serum albumin (BSA) could be adsorbed on BBC capillary at pH=5.0 (I=10^-5 mol/L), and then the adsorbed BSA could be released at pH=9.0 (I=0.1 mol/L). This switchable protein adsorption/desorption property of coated capillary was then used to preconcentrate proteins on-line for increasing the detection sensitivity of BSA in capillary electrophoresis (CE). With this method, a sensitivity enhancement factor (SEF) more than 5000 for BSA detection was obtained.
